[pardo]

It's quite nicely explain in their about page:

http://sugru.com/about/

"sugru is like modeling clay when you take it from its pack. Once it's exposed to air, it cures to a tough flexible silicone overnight using the moisture in the air. [It] is designed to stick to as many other materials as possible. It forms a strong bond to aluminium, steel, ceramics, glass and other materials including plastics like perspex. When sugru cures, it's flexible rather than rigid. Which means that you can repair things that need to be able to move like textiles, cables, or shoes."

[starkfist]

They should put a description on the front page. I though it was one of those sugar gels marketed to triathletes.

[ryanwaggoner]

I didn't get down that far on that page because the stuff at the top was so vague.

[pclark]

"a strong flexible clay - superb for bonding materials together."